2. Naming Unix Path Name Name Space as Memory

A semantic le system is an information storage system that provides exible associative access to the system's contents by automatically extracting attributes from les with le type speci c transducers. Associative access is provided by a conservative extension to existing tree-structured le system protocols, and by protocols that are designed speci cally for content based access. Compatiblity with existing le system protocols is provided by introducing the concept of a virtual directory. Virtual directory names are interpreted as queries, and thus provide exible associative access to les and directories in a manner compatible with existing software. Rapid attribute-based access to le system contents is implemented by automatic extraction and indexing of key properties of le system objects. The automatic indexing of les and directories is called \semantic" because user programmable transducers use information about the semantics of updated le system objects to extract the properties for indexing. Experimental results from a semantic le system implementation support the thesis that semantic le systems present a more e ective storage abstraction than do traditional tree structured le systems for information sharing and command level programming.